The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1991
Filed:
Aug. 15, 1989
Teruo Tsutsumi, Tama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
To read a document accurately and produce an image signal faithfully representing the document, an image reading method and apparatus adopts various means, of 'latching an average light-shielded signal in a digital form', 'using an average light-shielded signal resulting from averaging output signals of a plurality of light-shielded pixels as a black reference signal', 'replacing that part of an image signal in which an average light-shielded signal is larger than an effective pixel signal in level with a signal of a zero level', 'driving CCD sensors at such timing as to allow effective pixel signals output from the CCD sensors to be continuous in time' and 'setting DC offset voltages of signals output from CCD sensors to a predetermined clamp potential.'